The field of the invention is devices for locking electrical switches in one of their operating states, and particularly, the locking of electrical switches that are mounted on control panels.
There are many instances where it is desirable to lock electrically controlled equipment by disabling a switch. For example, in industrial applications safety standards may require that equipment be deenergized and locked in this state while maintenance is performed, or that certain equipment always remain operative while particular procedures are being performed. Traditionally, such switches have handles or hasps to which locks can be applied, or the switches are mounted in enclosures which can be locked.
As industrial equipment becomes more automated, manual controls have become more centralized. Whereas in the past, control switches may have been disconnects located near the equipment in lockable enclosures, industrial automation has produced centralized control panels with numerous manually operable switches and displays. In addition, industrial control systems are usually programmable and the function performed by control panel switches can be changed without rewiring them. There is a need for lockout devices which can be easily applied to control panel toggle switches in the event their operation must be securely controlled.